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- // based on the aes implimentation in triple sec
- // https://github.com/keybase/triplesec
- // which is in turn based on the one from crypto-js
- // https://code.google.com/p/crypto-js/
-
- var Buffer = require('safe-buffer').Buffer
-
- function asUInt32Array (buf) {
- if (!Buffer.isBuffer(buf)) buf = Buffer.from(buf)
-
- var len = (buf.length / 4) | 0
- var out = new Array(len)
-
- for (var i = 0; i < len; i++) {
- out[i] = buf.readUInt32BE(i * 4)
- }
-
- return out
- }
-
- function scrubVec (v) {
- for (var i = 0; i < v.length; v++) {
- v[i] = 0
- }
- }
-
- function cryptBlock (M, keySchedule, SUB_MIX, SBOX, nRounds) {
- var SUB_MIX0 = SUB_MIX[0]
- var SUB_MIX1 = SUB_MIX[1]
- var SUB_MIX2 = SUB_MIX[2]
- var SUB_MIX3 = SUB_MIX[3]
-
- var s0 = M[0] ^ keySchedule[0]
- var s1 = M[1] ^ keySchedule[1]
- var s2 = M[2] ^ keySchedule[2]
- var s3 = M[3] ^ keySchedule[3]
- var t0, t1, t2, t3
- var ksRow = 4
-
- for (var round = 1; round < nRounds; round++) {
- t0 = SUB_MIX0[s0 >>> 24] ^ SUB_MIX1[(s1 >>> 16) & 0xff] ^ SUB_MIX2[(s2 >>> 8) & 0xff] ^ SUB_MIX3[s3 & 0xff] ^ keySchedule[ksRow++]
- t1 = SUB_MIX0[s1 >>> 24] ^ SUB_MIX1[(s2 >>> 16) & 0xff] ^ SUB_MIX2[(s3 >>> 8) & 0xff] ^ SUB_MIX3[s0 & 0xff] ^ keySchedule[ksRow++]
- t2 = SUB_MIX0[s2 >>> 24] ^ SUB_MIX1[(s3 >>> 16) & 0xff] ^ SUB_MIX2[(s0 >>> 8) & 0xff] ^ SUB_MIX3[s1 & 0xff] ^ keySchedule[ksRow++]
- t3 = SUB_MIX0[s3 >>> 24] ^ SUB_MIX1[(s0 >>> 16) & 0xff] ^ SUB_MIX2[(s1 >>> 8) & 0xff] ^ SUB_MIX3[s2 & 0xff] ^ keySchedule[ksRow++]
- s0 = t0
- s1 = t1
- s2 = t2
- s3 = t3
- }
-
- t0 = ((SBOX[s0 >>> 24] << 24) | (SBOX[(s1 >>> 16) & 0xff] << 16) | (SBOX[(s2 >>> 8) & 0xff] << 8) | SBOX[s3 & 0xff]) ^ keySchedule[ksRow++]
- t1 = ((SBOX[s1 >>> 24] << 24) | (SBOX[(s2 >>> 16) & 0xff] << 16) | (SBOX[(s3 >>> 8) & 0xff] << 8) | SBOX[s0 & 0xff]) ^ keySchedule[ksRow++]
- t2 = ((SBOX[s2 >>> 24] << 24) | (SBOX[(s3 >>> 16) & 0xff] << 16) | (SBOX[(s0 >>> 8) & 0xff] << 8) | SBOX[s1 & 0xff]) ^ keySchedule[ksRow++]
- t3 = ((SBOX[s3 >>> 24] << 24) | (SBOX[(s0 >>> 16) & 0xff] << 16) | (SBOX[(s1 >>> 8) & 0xff] << 8) | SBOX[s2 & 0xff]) ^ keySchedule[ksRow++]
- t0 = t0 >>> 0
- t1 = t1 >>> 0
- t2 = t2 >>> 0
- t3 = t3 >>> 0
-
- return [t0, t1, t2, t3]
- }
-
- // AES constants
- var RCON = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36]
- var G = (function () {
- // Compute double table
- var d = new Array(256)
- for (var j = 0; j < 256; j++) {
- if (j < 128) {
- d[j] = j << 1
- } else {
- d[j] = (j << 1) ^ 0x11b
- }
- }
-
- var SBOX = []
- var INV_SBOX = []
- var SUB_MIX = [[], [], [], []]
- var INV_SUB_MIX = [[], [], [], []]
-
- // Walk GF(2^8)
- var x = 0
- var xi = 0
- for (var i = 0; i < 256; ++i) {
- // Compute sbox
- var sx = xi ^ (xi << 1) ^ (xi << 2) ^ (xi << 3) ^ (xi << 4)
- sx = (sx >>> 8) ^ (sx & 0xff) ^ 0x63
- SBOX[x] = sx
- INV_SBOX[sx] = x
-
- // Compute multiplication
- var x2 = d[x]
- var x4 = d[x2]
- var x8 = d[x4]
-
- // Compute sub bytes, mix columns tables
- var t = (d[sx] * 0x101) ^ (sx * 0x1010100)
- SUB_MIX[0][x] = (t << 24) | (t >>> 8)
- SUB_MIX[1][x] = (t << 16) | (t >>> 16)
- SUB_MIX[2][x] = (t << 8) | (t >>> 24)
- SUB_MIX[3][x] = t
-
- // Compute inv sub bytes, inv mix columns tables
- t = (x8 * 0x1010101) ^ (x4 * 0x10001) ^ (x2 * 0x101) ^ (x * 0x1010100)
- INV_SUB_MIX[0][sx] = (t << 24) | (t >>> 8)
- INV_SUB_MIX[1][sx] = (t << 16) | (t >>> 16)
- INV_SUB_MIX[2][sx] = (t << 8) | (t >>> 24)
- INV_SUB_MIX[3][sx] = t
-
- if (x === 0) {
- x = xi = 1
- } else {
- x = x2 ^ d[d[d[x8 ^ x2]]]
- xi ^= d[d[xi]]
- }
- }
-
- return {
- SBOX: SBOX,
- INV_SBOX: INV_SBOX,
- SUB_MIX: SUB_MIX,
- INV_SUB_MIX: INV_SUB_MIX
- }
- })()
-
- function AES (key) {
- this._key = asUInt32Array(key)
- this._reset()
- }
-
- AES.blockSize = 4 * 4
- AES.keySize = 256 / 8
- AES.prototype.blockSize = AES.blockSize
- AES.prototype.keySize = AES.keySize
- AES.prototype._reset = function () {
- var keyWords = this._key
- var keySize = keyWords.length
- var nRounds = keySize + 6
- var ksRows = (nRounds + 1) * 4
-
- var keySchedule = []
- for (var k = 0; k < keySize; k++) {
- keySchedule[k] = keyWords[k]
- }
-
- for (k = keySize; k < ksRows; k++) {
- var t = keySchedule[k - 1]
-
- if (k % keySize === 0) {
- t = (t << 8) | (t >>> 24)
- t =
- (G.SBOX[t >>> 24] << 24) |
- (G.SBOX[(t >>> 16) & 0xff] << 16) |
- (G.SBOX[(t >>> 8) & 0xff] << 8) |
- (G.SBOX[t & 0xff])
-
- t ^= RCON[(k / keySize) | 0] << 24
- } else if (keySize > 6 && k % keySize === 4) {
- t =
- (G.SBOX[t >>> 24] << 24) |
- (G.SBOX[(t >>> 16) & 0xff] << 16) |
- (G.SBOX[(t >>> 8) & 0xff] << 8) |
- (G.SBOX[t & 0xff])
- }
-
- keySchedule[k] = keySchedule[k - keySize] ^ t
- }
-
- var invKeySchedule = []
- for (var ik = 0; ik < ksRows; ik++) {
- var ksR = ksRows - ik
- var tt = keySchedule[ksR - (ik % 4 ? 0 : 4)]
-
- if (ik < 4 || ksR <= 4) {
- invKeySchedule[ik] = tt
- } else {
- invKeySchedule[ik] =
- G.INV_SUB_MIX[0][G.SBOX[tt >>> 24]] ^
- G.INV_SUB_MIX[1][G.SBOX[(tt >>> 16) & 0xff]] ^
- G.INV_SUB_MIX[2][G.SBOX[(tt >>> 8) & 0xff]] ^
- G.INV_SUB_MIX[3][G.SBOX[tt & 0xff]]
- }
- }
-
- this._nRounds = nRounds
- this._keySchedule = keySchedule
- this._invKeySchedule = invKeySchedule
- }
-
- AES.prototype.encryptBlockRaw = function (M) {
- M = asUInt32Array(M)
- return cryptBlock(M, this._keySchedule, G.SUB_MIX, G.SBOX, this._nRounds)
- }
-
- AES.prototype.encryptBlock = function (M) {
- var out = this.encryptBlockRaw(M)
- var buf = Buffer.allocUnsafe(16)
- buf.writeUInt32BE(out[0], 0)
- buf.writeUInt32BE(out[1], 4)
- buf.writeUInt32BE(out[2], 8)
- buf.writeUInt32BE(out[3], 12)
- return buf
- }
-
- AES.prototype.decryptBlock = function (M) {
- M = asUInt32Array(M)
-
- // swap
- var m1 = M[1]
- M[1] = M[3]
- M[3] = m1
-
- var out = cryptBlock(M, this._invKeySchedule, G.INV_SUB_MIX, G.INV_SBOX, this._nRounds)
- var buf = Buffer.allocUnsafe(16)
- buf.writeUInt32BE(out[0], 0)
- buf.writeUInt32BE(out[3], 4)
- buf.writeUInt32BE(out[2], 8)
- buf.writeUInt32BE(out[1], 12)
- return buf
- }
-
- AES.prototype.scrub = function () {
- scrubVec(this._keySchedule)
- scrubVec(this._invKeySchedule)
- scrubVec(this._key)
- }
-
- module.exports.AES = AES
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